<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      .sanjiao1 {
        /* height: 400px; */
        /* width: 200px; */
        width: 0;
        border-style: solid;
        border-color: transparent red red transparent;
        border-width: 200px 100px;
      }
      .sanjiao2 {
        width: 0;
        border-style: solid;
        border-color: transparent white white transparent;
        border-width: 100px 100px;
        position: absolute;
        top: 208px;
      }
    </style>
  </head>
  <body>
    <div class="sanjiao1"></div>
    <div class="sanjiao2"></div>
  </body>
</html>
